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- Title
- WHAT MECHANISMS UNDERLIE SYNCHRONOUS HATCHING IN LOGGERHEAD TURTLE NESTS?.
- Creator
- Field, Angela, Salmon, Michael, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
-
The goal of this study was to determine if hatching synchrony occurs in loggerhead sea turtle nests and if it does, what mechanism(s) promote that synchrony. Synchrony may occur because oviposition takes place during a single evening, and because incubation temperatures within the nest show relatively little variation; thus, rates of embryonic development among the eggs are similar ("temporal synchrony hypothesis"). Alternatively, synchrony might be enhanced through embryo-to-embryo...
Show moreThe goal of this study was to determine if hatching synchrony occurs in loggerhead sea turtle nests and if it does, what mechanism(s) promote that synchrony. Synchrony may occur because oviposition takes place during a single evening, and because incubation temperatures within the nest show relatively little variation; thus, rates of embryonic development among the eggs are similar ("temporal synchrony hypothesis"). Alternatively, synchrony might be enhanced through embryo-to-embryo communication that stimulates and synchronizes development ("coordinated hatching hypothesis"). Experiments were designed to distinguish between these two hypotheses. I found that if only a few embryos survive, temporal synchrony occurs. However, if many embryos survive, the duration of incubation and hatching shortens, presumably because embryonic movements inside soft-shelled eggs are detected by and transmitted between eggs and stimulate development, expediting hatching synchrony.
Show less - Date Issued
- 2020
- PURL
- http://purl.flvc.org/fau/fd/FA00013505
- Subject Headings
- Loggerhead turtle, Nests, Eggs—Incubation, Synchrony
- Format
- Document (PDF)
- Title
- Wading bird use of geographically isolated wetlands in the southeastern U.S. Coastal Plain.
- Creator
- Herteux, Camille E., Gawlik, Dale E., Smith, Lora L., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
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Geographically isolated wetlands (GIWs) within the southeastern U.S. Coastal Plain have been increasingly recognized for their importance in providing ecosystem services. These wetlands serve as valuable foraging and breeding habitat for wetland-dependent species, including wading birds. I quantified wading bird presence in GIWs in southwestern Georgia and determined the relative importance of factors influencing their use of these wetlands. I also examined the diet of a nesting colony of...
Show moreGeographically isolated wetlands (GIWs) within the southeastern U.S. Coastal Plain have been increasingly recognized for their importance in providing ecosystem services. These wetlands serve as valuable foraging and breeding habitat for wetland-dependent species, including wading birds. I quantified wading bird presence in GIWs in southwestern Georgia and determined the relative importance of factors influencing their use of these wetlands. I also examined the diet of a nesting colony of Little Blue Herons; a species experiencing population declines throughout most of the Southeast. I found that wetland-specific parameters were important factors in predicting wading bird use of GIWs, and wading birds utilized agricultural and natural wetlands differently depending on hydrological seasonality. Little Blue Herons were primarily consuming large anurans and anuran larvae, which are characteristic of agriculturally modified wetlands. The seasonal process of receding water levels in GIWs and subsequent concentration of
Show less - Date Issued
- 2018
- PURL
- http://purl.flvc.org/fau/fd/FA00013012
- Subject Headings
- Wetlands--Georgia, Wading birds, Herons--Ecology
- Format
- Document (PDF)
- Title
- Wading Bird Reproductive and Physiological Responses to Environmental Disturbance in a Managed Lake Ecosystem.
- Creator
- Chastant, Jennifer E., Gawlik, Dale E., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
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Wetlands are some of the most diverse and productive ecosystems on earth. Water-level fluctuations determine the ecological function of shallow lakes and wetlands. Currently, anthropogenic modification to water-level fluctuations is the leading source of ecological degradation in lake and wetland ecosystems worldwide. I used wading birds nesting in Lake Okeechobee, as a model system to address the challenges of environmental restoration within an ecosystem greatly impacted by anthropogenic...
Show moreWetlands are some of the most diverse and productive ecosystems on earth. Water-level fluctuations determine the ecological function of shallow lakes and wetlands. Currently, anthropogenic modification to water-level fluctuations is the leading source of ecological degradation in lake and wetland ecosystems worldwide. I used wading birds nesting in Lake Okeechobee, as a model system to address the challenges of environmental restoration within an ecosystem greatly impacted by anthropogenic activities. Specifically, I 1) identified environmental factors most important for predicting the number of wading bird nests, 2) tested the assumptions of both the match-mismatch and the threshold hypothesis by modeling the relationship between nesting success and prey density with foraging habitat availability, and 3) measured the stress response of Great (Ardea alba) and Snowy Egrets (Egretta thula) to hydrologically-mediated changes in food availability. Collectively, the results suggest that the number of nests was greatest when area of nesting substrate was high and water-levels were moderate (3.9 - 4.4 m). Nest numbers dropped when either nesting substrate or foraging habitat was limited. My investigation into the predictions of the match-mismatch and threshold hypotheses found that indeed, prey density can reduce or intensify the effects of a mismatch event. The interaction of prey density and foraging habitat availability was significant and positive in both models. Saturation thresholds existed for both fledging success (147 prey (m^2)^-1) and total productivity (189 prey (m^2)^-1), above which high concentrations of prey could sustain nesting when foraging habitat availability was low. Finally, my studies of the stress response support the hypothesis that hydrologic factors associated with prey availability play an important role in regulating nesting patterns, although the level of food limitation the birds experience at the lake was not as severe as expected. Model selection identified foraging habitat availability as most influential to the nestling Great Egret stress response, whereas foraging habitat availability and prey density both influenced nestling Snowy Egret stress response. Moreover, the Snowy Egret stress response was more sensitive to changes in prey availability than was the Great Egret stress response. Temperature and foraging conditions influenced yolk corticosterone concentrations for both egret species.
Show less - Date Issued
- 2016
- PURL
- http://purl.flvc.org/fau/fd/FA00004779
- Subject Headings
- Wetland ecology., Estuarine ecology., Water birds--Habitat., Predation (Biology)
- Format
- Document (PDF)
- Title
- Wading bird prey production and prey selection in a dynamic wetland.
- Creator
- Klassen, Jessica A., Gawlik, Dale E., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Anthropogenic impacts, such as habitat destruction and spread of exotic species, are contributing to the sixth major extinction event in Earth’s history. To develop effective management and conservation plans, it is important to understand the ecological drivers of at-risk populations, assess the ability of a population to adapt to environmental change, and develop research methods for long-term ecosystem monitoring. I used wading birds nesting in the Florida Everglades, USA as a model system...
Show moreAnthropogenic impacts, such as habitat destruction and spread of exotic species, are contributing to the sixth major extinction event in Earth’s history. To develop effective management and conservation plans, it is important to understand the ecological drivers of at-risk populations, assess the ability of a population to adapt to environmental change, and develop research methods for long-term ecosystem monitoring. I used wading birds nesting in the Florida Everglades, USA as a model system to address the challenges of managing and monitoring populations within an ecosystem greatly impacted by anthropogenic activities. Specifically, my project investigated 1) the prey selection of wading bird species, and the role of prey and foraging habitat availability on annual nesting numbers, 2) the ability of using diet change to predict species adaptability to a rapidly changing environment, and 3) the use of sensory data to provide low-cost, long-term monitoring of dynamic wetlands. I found that tricolored herons, snowy egrets, and little blue herons consumed marsh fish larger than those generally available across the landscape. Additionally, number of nests initiated by tricolored herons, snowy egrets, and little blue herons was strongly correlated with the annual densities of large fish available within the Everglades landscape. Conversely, number of nests initiated by wood storks, great egrets, and white ibises was more correlated with the amount of foraging habitat availability across the nesting season. Wood stork diets changed considerably since the 1960’s, consisting of mainly sunfish and exotic fish as opposed to marsh fishes dominant in historical diet studies. Storks also consumed more exotic fish species than they did historically. This diet plasticity and the species’ ability to exploit anthropogenic habitats may be conducive to maintaining population viability as storks experience widespread human-induced changes to their habitat. Sensory-only data models generated complementary results to models that used site-specific field data. Additionally, sensory-only models were able to detect different responses between size classes of fish to the processes that increase their concentrations in drying pools. However, the degree to which sensory variables were able to fit species data was dependent upon the ability of sensors to measure species-specific population drivers and the scale at which sensors can measure environmental change.
Show less - Date Issued
- 2016
- PURL
- http://purl.flvc.org/fau/fd/FA00004716
- Subject Headings
- Charadriiformes -- Habitat -- Florida -- Everglades, Ciconiiformes -- Habitat -- Florida -- Everglades, Everglades National Park (Fla.) -- Environmental conditions, Predation (Biology), Wetland ecology, Wildlife conservation
- Format
- Document (PDF)
- Title
- VISUALIZING NANO-SCALE SYNAPTIC CHANGES DURING SINGLE DENDRITIC SPINE LONG-TERM POTENTIATION BY CORRELATIVE LIGHT AND ELECTRON MICROSCOPY.
- Creator
- Sun, Ye, Yasuda, Ryohei, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
-
Dendritic spines are the major sites for receiving excitatory synaptic inputs and play important roles in neuronal signal transduction, memory storage and neuronal circuit organization. Structural plasticity of dendritic spines is correlated with functional plasticity, and is critical for learning and memory. Visualization of the changes of dendritic spines at the ultrastructural level that specifically correlated with their function changes in high throughput would shed light on detailed...
Show moreDendritic spines are the major sites for receiving excitatory synaptic inputs and play important roles in neuronal signal transduction, memory storage and neuronal circuit organization. Structural plasticity of dendritic spines is correlated with functional plasticity, and is critical for learning and memory. Visualization of the changes of dendritic spines at the ultrastructural level that specifically correlated with their function changes in high throughput would shed light on detailed mechanisms of synaptic plasticity. Here we developed a correlative light and electron microscopy workflow which combines two-photon MNI-glutamate uncaging, pre-embedding immunolabeling, Automatic Tape-collecting Ultramicrotome sectioning and scanning electron microscopy imaging. This method bridges two different visualization platforms, directly linking ultrastructure and function at the level of individual synapses. With this method, we successfully relocated single dendritic spines that underwent long-term potentiation (LTP) induced by two-photon MNI-glutamate uncaging, and visualized their ultrastructures and AMPA receptors distribution at different phases of LTP in high throughput.
Show less - Date Issued
- 2020
- PURL
- http://purl.flvc.org/fau/fd/FA00013433
- Subject Headings
- Dendritic Spines, Neuroplasticity, Visualization, Microscopy, Long-Term Potentiation--physiology, Neurons--ultrastructure
- Format
- Document (PDF)
- Title
- Visual wavelength discrimination by the loggerhead turtle, Caretta caretta.
- Creator
- Young, Morgan, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Little is known about the visual capabilities of marine turtles. The ability to discriminate between colors has not been adequately demonstrated on the basis of behavioral criteria. I used a three-part methodology to determine if color discrimination occurred. FIrst, I exposed naèive, light-adapted hatchlings to either a blue, green or yellow light. I manipulated light intensity to obtain a behavioral phototaxis threshold to each color, which provided a range of intensities we knew turtles...
Show moreLittle is known about the visual capabilities of marine turtles. The ability to discriminate between colors has not been adequately demonstrated on the basis of behavioral criteria. I used a three-part methodology to determine if color discrimination occurred. FIrst, I exposed naèive, light-adapted hatchlings to either a blue, green or yellow light. I manipulated light intensity to obtain a behavioral phototaxis threshold to each color, which provided a range of intensities we knew turtles could detect. Second, I used food to train older turtles to swim toward one light color, and then to discriminate between the rewarded light and another light color ; lights were presented at intensities equally above the phototaxis threshold. Lastly, I varied light intensity so that brightness could not be used as a discrimination cue. Six turtles completed this task and showed a clear ability to select a rewarded over a non-rewarded color, regardless of stimulus intensity. Turtles most rapidly learned to associate shorter wavelengths (blue) with food. My results clearly show loggerheads have color vision. Further investigation is required to determine how marine turtles exploit this capability.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3352879
- Subject Headings
- Color vision, Visual discrimination, VIsual perception, Selectivity (Psychology), Photoreceptors, Loggerhead turtle, Orientation, Sea turtles, Orientation, Animal navigation
- Format
- Document (PDF)
- Title
- Visual and electrosensory ecology of batoid elasmobranchs.
- Creator
- Bedore, Christine N., Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
The electrosensory and visual adaptations of elasmobranchs to the environment have been more studied than most other senses, however, work on these senses is mostly limited to descriptive analyses of sensitivity, morphology, and behavior. The goal of this work was to explore electrosensory and visual capabilities in a more ecological context. To gain an understanding of the content of bioelectric signals, the magnitude and frequency of these stimuli were recorded from a broad survey of...
Show moreThe electrosensory and visual adaptations of elasmobranchs to the environment have been more studied than most other senses, however, work on these senses is mostly limited to descriptive analyses of sensitivity, morphology, and behavior. The goal of this work was to explore electrosensory and visual capabilities in a more ecological context. To gain an understanding of the content of bioelectric signals, the magnitude and frequency of these stimuli were recorded from a broad survey of elasmobranch prey items... Color vision adaptations also correlated to the photic environment of each species; cownose rays inhabit turbid, green-dominated waters and had two cone visual pigments that maximize contrast of objects against the green background... Yellow stingrays were trichromatic and likely possess the ability to discriminate colors in their clear, reef and seagrass habitats, which are spectrally rich. Both species showed evidence of ultraviolet sensitivity, which may aid in predator and conspecific detection as an enhanced communication channel. Future studies should investigate the integration of sensory input and sensory involvement in intraspecific communication to gain more insight into ecological adaptations.
Show less - Date Issued
- 2013
- PURL
- http://purl.flvc.org/fcla/dt/3362337
- Subject Headings
- Visual discrimination, Adaptation (Biology), Animal ecophysiology, Chondrichthyes, Physiology
- Format
- Document (PDF)
- Title
- Visual adaptations in sharks, skates and rays.
- Creator
- McComb, Dawn Michelle, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
The central importance of vision to an organism is evident in the anatomical and physiological adaptations within the eye that can be correlated to the organism's behavior and ecology. The goal of this study was to perform a functional analysis of adaptations within the elasmobranch visual system. An integrative approach was used to examine morphological and physiological adaptations in several species and link these adaptations to phylogeny, locomotion, habitat, behavior and ecology....
Show moreThe central importance of vision to an organism is evident in the anatomical and physiological adaptations within the eye that can be correlated to the organism's behavior and ecology. The goal of this study was to perform a functional analysis of adaptations within the elasmobranch visual system. An integrative approach was used to examine morphological and physiological adaptations in several species and link these adaptations to phylogeny, locomotion, habitat, behavior and ecology. Functional aspects investigated were eye position, pupil shape, spectral sensitivity, temporal resolution, the extent of the visual field and ultimately the integration of the visual and electrosensory systems. The elasmobranch eye adapts to the light environment of its habitat. Sharks from similar habitats had similar spectral sensitivities such as the bonnethead and blacknose sharks, both maximally sensitive to blue light of 480 nm. The spectral sensitivity of the scalloped hammerhead, which lives in a different environment, was maximally sensitive to green light (530 nm). The temporal characteristics of the eye also matched habitat and lifestyle. Species experiencing variable light conditions exhibited increased critical flicker-fusion frequencies, such as the bonnethead (31 Hz) and scalloped hammerhead (27 Hz), in contrast to deeper or more nocturnal species such as the blacknose shark (18 Hz). Elasmobranch visual fields correlated to each species' lifestyle, habitat and foraging strategy. Expansive monocular views, including a 360° panoramic view in the yellow stingray, were measured in species that rely on vision for vigilance against predators., The Atlantic stingray possessed large binocular overlaps (72°), which provided depth perception useful for tracking prey. By comparison, the frontal binocular overlaps of hammerhead species were larger than sharks with a more conventional head shape.This study quantified the range of the electrosensory system and the exte the visual field of several shark species, confirming both systems overlap around the head facilitating near seamless visual and electrosensory sensory function relevant to prey detection. The findings of this study indicate that ambient environmental light strongly influenced the function of the elasmobranch eye and that the extent of species' visual fields correlated with aspects of their morphology, locomotion and ecology.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/216410
- Subject Headings
- Visual discrimination, Chondrichthyes, Embryology, Form perception, Adaptation (Biology), Aquatic animals, Physiology
- Format
- Document (PDF)
- Title
- Vertebrate and Invertebrate Commensals in Gopher Tortoise Burrows of Southeast Florida.
- Creator
- Hipps, Amanda Cristina, Moore, Jon A., Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
-
Gopher tortoise (Gopherus Polyphemus) burrows provide a unique microhabitat used by hundreds of vertebrate and invertebrate species. Prior to this study, limited information was available regarding burrow commensal species in southeast Florida, especially for invertebrate taxa. This study is an in-depth investigation of vertebrate and invertebrate gopher tortoise burrow commensals and is the first to document obligate invertebrate commensals (OIC) in this region. The objective was to test a...
Show moreGopher tortoise (Gopherus Polyphemus) burrows provide a unique microhabitat used by hundreds of vertebrate and invertebrate species. Prior to this study, limited information was available regarding burrow commensal species in southeast Florida, especially for invertebrate taxa. This study is an in-depth investigation of vertebrate and invertebrate gopher tortoise burrow commensals and is the first to document obligate invertebrate commensals (OIC) in this region. The objective was to test a variety of noninvasive methods effective for surveying commensals, compile an account of species dependent on gopher tortoise burrows in southeast Florida, accumulate information on threatened, endangered, and invasive species, add to the distributional information on OIC’s, and present information to land managers. Three pine flatwoods and three scrub habitats, with varying degrees of management were surveyed. Eighty-nine species were identified. This study was a substantial step toward documenting gopher tortoise burrow commensals in this region.
Show less - Date Issued
- 2019
- PURL
- http://purl.flvc.org/fau/fd/FA00013378
- Subject Headings
- Gopher tortoise, Niche (Ecology), Commensalism, Keystone species
- Format
- Document (PDF)
- Title
- Vascular endothelial growth factor (VEGF), BCL-2, and BAX expression in fibropapilloma tumor tissue and skin tissue of sea turtles.
- Creator
- Bancalari-Schmidlapp, Angela., Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
In sea turtles, the study of the etiology and development of fibropapillomatosis is not fully understood. Sea turtle fibropapillomatosis is a disease characterized by the proliferation of skin fibropapillomas and occasional internal fibromas. In this study, sea turtle fibropapilloma tumor and healthy tissue samples were used to look at VEGF, BCL-2 and Bax expression. Cancer tumors have a well established pattern of protein expression that involves overexpression of vascular endothelial growth...
Show moreIn sea turtles, the study of the etiology and development of fibropapillomatosis is not fully understood. Sea turtle fibropapillomatosis is a disease characterized by the proliferation of skin fibropapillomas and occasional internal fibromas. In this study, sea turtle fibropapilloma tumor and healthy tissue samples were used to look at VEGF, BCL-2 and Bax expression. Cancer tumors have a well established pattern of protein expression that involves overexpression of vascular endothelial growth factor (VEGF), responsible for the growth of new blood vessels, and a high BCL-2 to Bax ratio that leads to uncontrolled cell proliferation. Real time PCR was used to analyze VEGF expression, and Western blot techniques were used to measure BCL-2 and Bax expression. The results indicated that expression of VEGF was not significantly higher in tumor vs. skin tissue. For the differential expression of BCL-2 and Bax, the results were not in agreement with the established levels found in cancer studies, showing no significant change in BCL-2 expression and significantly higher levels of Bax in tumor vs. healthy tissue.
Show less - Date Issued
- 2009
- PURL
- http://purl.flvc.org/FAU/209981
- Subject Headings
- Sea turtles, Physiology, Cancer, Pathophysiology, Vascular endothelial growth factors, Pathophysiology, Cellular signal transduction
- Format
- Document (PDF)
- Title
- Utilization of Genomic Tools to Enhance the Commercial Aquaculture of the Florida Pompano Trachinotus carolinus.
- Creator
- King, Laura Elizabeth, Wills, Paul S., Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
-
The goal of this project is to gain access to valuable genetic information that will be utilized to create a genetics-based selective breeding program. This selective breeding program will be implemented to produce and maintain a healthy and diverse breeding stock of the Florida Pompano Trachinotus carolinus. The Florida Pompano is a popular food fish found in abundance off Florida's east and west coasts. There has been interest in the aquaculture of this species for decades with minimal...
Show moreThe goal of this project is to gain access to valuable genetic information that will be utilized to create a genetics-based selective breeding program. This selective breeding program will be implemented to produce and maintain a healthy and diverse breeding stock of the Florida Pompano Trachinotus carolinus. The Florida Pompano is a popular food fish found in abundance off Florida's east and west coasts. There has been interest in the aquaculture of this species for decades with minimal success. With recent improvements in aquaculture systems and nutrition, now is the time to bring this fish to commercialization. The main research objectives of this study are to create a bioinformatics workflow to generate a draft whole-genome of the Florida Pompano, identify variation sites within this genome, and run a comparative analysis with two closely related Trachinotus species, Permit T. falcatus and Palometa T. goodei. These two species were chosen because they are found in the same environment as the Florida Pompano but grow to substantially different sizes. To sequence and assemble the whole genome of the Florida Pompano, a hybrid method was applied using long and short-read sequencing technologies. The draft genome was found to be 733.5 Mb in length with a total of 26,891 protein-coding genes. Sites of variation within this assembled genome were identified using a 2b-RAD sequencing method on 62 individuals collected off Florida’s east and gulf coasts.
Show less - Date Issued
- 2023
- PURL
- http://purl.flvc.org/fau/fd/FA00014181
- Subject Headings
- Florida pompano, Aquaculture, Genomics
- Format
- Document (PDF)
- Title
- Using Synthetic Biology to Create a Safe and Stable Ebola Surrogate for Effective Development of Detection and Therapy Platforms.
- Creator
- Holmes, Douglas, Esiobu, Nwadiuto, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
-
Ebolavirus is responsible for a deadly hemorrhagic fever that has claimed thousands of lives in Africa and could become a global health threat. Because of the danger of infection, novel Ebola research is restricted to BSL-4 laboratories; this slows progress due to both the cost and expertise required to operate these laboratories. The development of a safe surrogate would speed research and reduce risk to researchers. Two highly conserved Ebola gene segments—from the glycoprotein and...
Show moreEbolavirus is responsible for a deadly hemorrhagic fever that has claimed thousands of lives in Africa and could become a global health threat. Because of the danger of infection, novel Ebola research is restricted to BSL-4 laboratories; this slows progress due to both the cost and expertise required to operate these laboratories. The development of a safe surrogate would speed research and reduce risk to researchers. Two highly conserved Ebola gene segments—from the glycoprotein and nucleoprotein genes—were designed with modifications preventing expression while maintaining sequence integrity, spliced into high copy number plasmids, cloned into E.coli, and tested for stability, safety, and potential research applications. The surrogates were stable over 2-3 months, had a negligible mutation rate (<0.165% over the experiment), and were detectable in human blood down to 5.8E3-1.17E4 surrogates/mL. These protocols could be used to safely simulate other pathogens and promote infectious disease treatment and detection research.
Show less - Date Issued
- 2018
- PURL
- http://purl.flvc.org/fau/fd/FA00013015
- Subject Headings
- Ebolavirus, Infectious disease research, Ebola virus disease, Synthetic biology
- Format
- Document (PDF)
- Title
- USING ELECTROSHOCK TO PROBE MECHANISMS OF HERBICIDE NEUROTOXICITY AND NOVEL NEUROPROTECTIVE COMPOUNDS IN CAENORHABDITIS ELEGANS AND DROSOPHILA MELANOGASTER.
- Creator
- Naraine, Akshay S., Dawson-Scully, Kenneth, Milton, Sarah, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
-
The communication in the nervous system is a pharmacological balance between excitatory and inhibitory signals, and seizure behavior is one of the most common manifestations of when an imbalance occurs. Environmental toxins can cause significant disruption of excitation-inhibition balance, but while some toxins, like nerve agents, have known targets and require novel antidotes, some have unknown neurobiological mechanisms and require exploration. Of particular concern, there is little...
Show moreThe communication in the nervous system is a pharmacological balance between excitatory and inhibitory signals, and seizure behavior is one of the most common manifestations of when an imbalance occurs. Environmental toxins can cause significant disruption of excitation-inhibition balance, but while some toxins, like nerve agents, have known targets and require novel antidotes, some have unknown neurobiological mechanisms and require exploration. Of particular concern, there is little knowledge on how herbicides may affect neurological signaling. Glyphosate, the world’s most popular herbicide, was found to be in 80% of people’s urine, and since it is so prevalent, it is critical to understand its impact on both excitatory and inhibitory signaling. We used an electroshock assay developed for C. elegans to uncover evidence that glyphosate, and the commercial formula Roundup, disrupted the excitation-inhibition balance by blocking GABA-A receptors. This presented a novel hypothesis of an inhibitory neurobiological target for glyphosate. As glutamate is the major excitatory neurotransmitter in the human central nervous system, an electrophysiology assay using Drosophila was used and found that Roundup, but not glyphosate, reduced synaptic viability. This result directs attention to the undisclosed adjuvant component which may have a significant effect on synaptic transmission, though the exact mechanism requires further investigation.
Show less - Date Issued
- 2023
- PURL
- http://purl.flvc.org/fau/fd/FA00014151
- Subject Headings
- Seizures, Neurotoxins, Neuroprotective agents, Herbicides--Toxicology
- Format
- Document (PDF)
- Title
- UNDERSTANDING THE PHENOTYPE: A STUDY ON HOW THE INCUBATION ENVIRONMENT INFLUENCES EMBRYO GROWTH, SEX, AND SEX RATIOS IN TURTLES WITH TEMPERATURE DEPENDENT SEX DETERMINATION.
- Creator
- Tezak, Boris M., Wyneken, Jeanette, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
-
Currently, one of the most critical research priorities in wildlife science is to understand, describe, and predict how the unprecedented rate of climate change will impact organisms and ecosystems. This is particularly essential for thermally sensitive organisms that are already imperiled, such as turtles. For all known turtle species, the nest incubation environment plays a critical role in many developmental processes which can directly influence a number of phenotypic traits, such as body...
Show moreCurrently, one of the most critical research priorities in wildlife science is to understand, describe, and predict how the unprecedented rate of climate change will impact organisms and ecosystems. This is particularly essential for thermally sensitive organisms that are already imperiled, such as turtles. For all known turtle species, the nest incubation environment plays a critical role in many developmental processes which can directly influence a number of phenotypic traits, such as body size, mass, locomotor performance, behavior and even sex. Most chelonians (and all extant marine turtles) possess a mechanism known as temperature dependent sex determination (TSD), whereby gonads differentiate into ovaries or testes depending on the incubation temperature of the eggs during a critical period of embryonic development. The rapid rate of climate change highlights the need for a clear understanding of how potential changes in the nest environment will affect turtle development and hatchling phenotype. However, it is poorly understood how different environmental factors interact with the embryo’s own genetic program to produce a specific phenotype. My thesis aims to (i) provide a better understanding of the complex relationship between the developing embryo and the nest environment and its effect on hatchling phenotype, and (ii) offer a solution to the difficulties associated with identifying primary sex ratios in turtle species with TSD.
Show less - Date Issued
- 2019
- PURL
- http://purl.flvc.org/fau/fd/FA00013421
- Subject Headings
- Phenotype, Temperature-dependent sex determination, Turtles--Growth
- Format
- Document (PDF)
- Title
- UNDERSTANDING THE MICROBIAL ASPECTS OF BRAZILIAN PEPPER TREE (SCHINUS TEREBINTHIFOLIUS) INVASION IN FLORIDA.
- Creator
- Dawkins, Karim, Esiobu, Nwadiuto, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
-
Emerging insights on the role of microbiomes in the sustainability of ecosystems and plant cover are transforming knowledge-driven agro-environmental management practices. For more than a century, the Brazilian pepper tree -BP (Schinus terebinthifolius), a category 1 invasive plant in Florida has defied numerous conventional control measures directed at its well-known ecology. This dissertation is one of the pioneer studies designed to determine whether microorganisms play a role in the...
Show moreEmerging insights on the role of microbiomes in the sustainability of ecosystems and plant cover are transforming knowledge-driven agro-environmental management practices. For more than a century, the Brazilian pepper tree -BP (Schinus terebinthifolius), a category 1 invasive plant in Florida has defied numerous conventional control measures directed at its well-known ecology. This dissertation is one of the pioneer studies designed to determine whether microorganisms play a role in the aggressive invasion of BP in Florida and examine potential mechanisms with the goal of creating supplemental restoration tools. To test the hypothesis that enhanced mutualism of Brazilian pepper tree with microbes, compounded by relatively low biotic resistance of Florida soils is a critical driver of its invasion, plant biomass indices, metagenomics analysis of microbial community shifts, electron microscopy of endomycorrhizal infection and qPCR of key rhizobacterial taxa were measured. A multifactorial grow-room experiment was conducted simulating invasion with BP and two Florida natives (Pinus elliottii and Bidens alba) in a sterile, bioinoculant supplemented, and non-sterile control soils with various plant combinations.
Show less - Date Issued
- 2022
- PURL
- http://purl.flvc.org/fau/fd/FA00014017
- Subject Headings
- Brazilian pepper tree, Arbuscular mycorrhizas, Invasive plants
- Format
- Document (PDF)
- Title
- Tropical crustose coralline algal community and individual growth responses to light and elevated pCO2.
- Creator
- Dutra, Elizabeth A., Koch, Marguerite, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
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Crustose coralline algae (CCA) are important reef stabilizers and their susceptibility to anthropogenic climate change and ocean acidification (OA) is of concern. Ocean acidification effects on benthic algal communities were determined by the response of CCA, fleshy macroalgae and microalgae to the interaction of pCO2 and light. I examined if elevated pCO2 and light influences CCA dominance by assessing their growth, recruitment and calcification. Elevated pCO2 under natural reef diurnal CO2...
Show moreCrustose coralline algae (CCA) are important reef stabilizers and their susceptibility to anthropogenic climate change and ocean acidification (OA) is of concern. Ocean acidification effects on benthic algal communities were determined by the response of CCA, fleshy macroalgae and microalgae to the interaction of pCO2 and light. I examined if elevated pCO2 and light influences CCA dominance by assessing their growth, recruitment and calcification. Elevated pCO2 under natural reef diurnal CO2 cycles did not significantly affect CCA percent cover, calcification rates or survival of adult CCA lobes. No significant community pCO2 effects were observed, rather light controlled dominance. The percent cover of microalgae increased in highlight, while CCA increased in the shade. My results indicate that algal response to irradiance is a more significant driver of reef benthic algal change than pCO2 levels predicted for 2100; however, this conclusion should be corroborated in longer-term and in field experiments.
Show less - Date Issued
- 2015
- PURL
- http://purl.flvc.org/fau/fd/FA00004365, http://purl.flvc.org/fau/fd/FA00004365
- Subject Headings
- Marine algae, Algal communities--Monitoring, Coral reef ecology
- Format
- Document (PDF)
- Title
- Trophic linkages of primary producers and consumers in fringing mangroves of tropical lagoons.
- Creator
- Kieckbusch, David Keith, Florida Atlantic University, Koch, Marguerite, Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
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Stable carbon and nitrogen isotope ratios were analyzed to investigate the trophic linkages between primary producers and consumers in fringing mangrove ecosystems of The Bahamas and Biscayne Bay, Florida. The isotope ratios, in conjunction with stomach content analysis, were used to trace the flow of organic matter from the primary organic sources (mangroves, seagrass and macro-algae) to primary consumers and ultimately to the gray snapper (Lutjanus griseus). We found the mean delta^13C...
Show moreStable carbon and nitrogen isotope ratios were analyzed to investigate the trophic linkages between primary producers and consumers in fringing mangrove ecosystems of The Bahamas and Biscayne Bay, Florida. The isotope ratios, in conjunction with stomach content analysis, were used to trace the flow of organic matter from the primary organic sources (mangroves, seagrass and macro-algae) to primary consumers and ultimately to the gray snapper (Lutjanus griseus). We found the mean delta^13C value of the primary consumers (-17.1%) to be closely related to the mean values of the macro-algal material (-16.7%) and the seagrass (-10.5%) with very little correlation to the carbon signature of mangroves (mean = -27.4%). Our results suggest the ultimate source of carbon for the primary and secondary consumers, located at our study sites, is algal and seagrass material, individually or possibly as a mixture, and that mangroves are not the sole source of carbon in these systems.
Show less - Date Issued
- 2001
- PURL
- http://purl.flvc.org/fcla/dt/12754
- Subject Headings
- Mangrove ecology, Food chains (Ecology)
- Format
- Document (PDF)
- Title
- Toxicity and availability of copper and zinc to queen conch: implications for larval recruitment in the Florida Keys.
- Creator
- Garr, Amber L., Charles E. Schmidt College of Science, Department of Biological Sciences
- Abstract/Description
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The presence of heavy metals and other pollutants is detrimental to marine ecosystems. The queen conch, once an important fisheries species in the Florida Keys, has not sufficiently recovered after a 25-year fishery closure. Research has shown high levels of copper and zinc in the gonads and digestive glands of adult conch found in the nearshore waters. Four sites relevant to queen conch larval recruitment were tested in 2010 for the presence of copper and zinc in the water, phytoplankton,...
Show moreThe presence of heavy metals and other pollutants is detrimental to marine ecosystems. The queen conch, once an important fisheries species in the Florida Keys, has not sufficiently recovered after a 25-year fishery closure. Research has shown high levels of copper and zinc in the gonads and digestive glands of adult conch found in the nearshore waters. Four sites relevant to queen conch larval recruitment were tested in 2010 for the presence of copper and zinc in the water, phytoplankton, sediment, and seagrass epiphytes over seven months. Both metals were detected in all sample types and no seasonal or geographical differences were detected. Surface water concentrations from the field were used to conduct acute and chronic toxicity tests on various ages of queen conch larvae and their phytoplankton food source. When zinc concentrations (0-40 (So(Bg/L) similar to those measured in situ were used, there was no significant impact on conch larval survival although some velar lobe de velopment was impaired. However, field concentrations of copper (0-15 (So(Bg/L), which often surpassed water quality standards, negatively impacted growth, survival, and development of the larvae. Chronic exposure to copper, through the water and food, disrupted the metamorphic success of competent larvae and decreased post-metamorphosis survival. Exposure to copper at later life stages increased mortality, suggesting that heavy metals have a negative effect on larval recruitment in localized areas of the Florida Keys. Structural equation modeling revealed that copper and zinc are moving through the systems differently and are best represented by two different models.
Show less - Date Issued
- 2012
- PURL
- http://purl.flvc.org/FAU/3342102
- Subject Headings
- Gastropoda, Habitat, Queen conch, Conservation, Marine invertebrates, Larvae, Trace elements, Environmental aspects
- Format
- Document (PDF)
- Title
- TO BUILD AN INVASIVE PREDATOR: INVESTIGATING THE MECHANICAL ROLE OF LIONFISH SPINES ON DEFENSE.
- Creator
- Galloway, Katherine Ann, Porter, Marianne E., Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
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The red lionfish, Pterois volitans, has arguably become the most successful marine invasive species to date. Yet, despite the invasion success of P. volitans, little is known about the morphology, physiology, and ecology of this species in their native and invaded habitats. The majority of recent studies have focused on the migration of P. volitans into new regions, digestion, and bacterial infections. Knowledge is lacking on the body plan of the invasive lionfish, specifically the numerous...
Show moreThe red lionfish, Pterois volitans, has arguably become the most successful marine invasive species to date. Yet, despite the invasion success of P. volitans, little is known about the morphology, physiology, and ecology of this species in their native and invaded habitats. The majority of recent studies have focused on the migration of P. volitans into new regions, digestion, and bacterial infections. Knowledge is lacking on the body plan of the invasive lionfish, specifically the numerous venomous spines that are protruding outward, making the body less streamlined. In this study we quantified the mechanical properties (bending and puncture) of the venomous spines of P. volitans, and related these properties to the cross-sectional morphology. We also documented variation in the cross-sectional morphology of spines from other lionfish species in their native regions. Lastly, we documented the dorsal spine joint morphology of the first three dorsal spines and the in situ range of motion as tissues were removed. We found that the long, numerous dorsal spines absorb more energy but are less stiff than the pelvic and anal spines. In addition, we found that the anal and pelvic spines are more effective at puncturing buccal skin from sharks and grouper. We found that the removal of connective tissue significantly changes lateral movement (abduction) for the first three dorsal spines. The removal of the fin sheath significantly alters forward movement (extension) for the first two dorsal spines. From morphology, mechanical property, and range of motion data for P. volitans, we propose that the numerous long dorsal spines are primarily used for intimidation, and are not as effective defense structures as the pelvic and anal spines. Having a substantial amount of intimidating, venomous spines may allow for the lionfish to conserve energy for other highly metabolically costly activities other than warding off predators, such as digestion and reproduction. Future studies could focus on the amount of venom in each spine, how long it takes for the venom to be made and replaced, how the venomous spines affect hydrodynamic flow, and in vivo range of motion during swimming and striking.
Show less - Date Issued
- 2020
- PURL
- http://purl.flvc.org/fau/fd/FA00013512
- Subject Headings
- Red lionfish, Pterois volitans, Spines (Zoology), Mechanical properties of biological structures, Biomechanics
- Format
- Document (PDF)
- Title
- THREE-DIMENSIONAL MOVEMENT AND HABITAT USE OF YOUNG WHITE SHARKS (CARCHARODON CARCHARIAS) IN THE NORTHWEST ATLANTIC OCEAN.
- Creator
- Shaw, Rachel Lynn, Ajemian, Matthew, Florida Atlantic University, Department of Biological Sciences, Charles E. Schmidt College of Science
- Abstract/Description
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Recent research confirmed white shark (Carcharodon carcharias) nursery habitat off Long Island, New York; however, additional research is required to determine the habitat use and fine-scale movements of young-of-the-year and juvenile white sharks within this nursery. Between 2016 and 2019, twenty-five white sharks were fitted with satellite and acoustic tags to better define habitat use. Individuals exhibited horizontal movements parallel to Long Island’s southern shoreline and coastal New...
Show moreRecent research confirmed white shark (Carcharodon carcharias) nursery habitat off Long Island, New York; however, additional research is required to determine the habitat use and fine-scale movements of young-of-the-year and juvenile white sharks within this nursery. Between 2016 and 2019, twenty-five white sharks were fitted with satellite and acoustic tags to better define habitat use. Individuals exhibited horizontal movements parallel to Long Island’s southern shoreline and coastal New Jersey. Log-likelihood chi-square analyses determined preference for water column depth, SSTs, sea surface salinities, and chlorophyll a concentration. Vertical analysis of diving behavior revealed swimming behavior primarily in the upper 20 m of the water column, in temperatures between 18°C and 20°C. Generalized additive mixed modeling suggested SSTs above 20.5°C affected dive depth. These results can help improve characterization of essential fish habitat for young white sharks and provide data to determine the species’ susceptibility to anthropogenic activities.
Show less - Date Issued
- 2020
- PURL
- http://purl.flvc.org/fau/fd/FA00013440
- Subject Headings
- Carcharodon carcharias, White shark, Marine nurseries, Sharks--Ecology
- Format
- Document (PDF)